Disquisitions on Original Antigenic Sin. II. Proof in lower creatures

Area of Science:

• Immunology
• Virology

Background:

• The hypothesis of Original Antigenic Sin (OAS) suggests a restricted anamnestic response.
• A proposed trapping mechanism may deflect antigens between cells.

Purpose of the Study:

• To experimentally validate the two core assumptions of the OAS hypothesis.
• To investigate the role of antigen trapping in immune responses.

Main Methods:

• Experiments were conducted using rabbits.
• Whole-body X-irradiation was used to assess primary versus secondary antibody production.
• Animals were challenged with related antigens and antigen mixtures.

Main Results:

• X-irradiation abolished primary antibody production but left OAS manifestations unaffected, supporting the first assumption.
• Challenging primary immune animals with large antigen doses induced cross-reactive antibodies followed by a primary response.
• Vaccinated animals given large booster doses showed a compound response, demonstrating a corollary of the antigen trapping mechanism.

Conclusions:

• The findings validate the restricted anamnestic nature of OAS.
• Evidence supports the existence of an antigen trapping mechanism in immune responses.
• Results inform theories on antibody production and immune memory.